libstdc++-v3/testsuite/experimental/algorithm/sample.cc

   1 // Copyright (C) 2014-2018 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 3, or (at your option)
   7 // any later version.
   8
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING3.  If not see
  16 // <http://www.gnu.org/licenses/>.
  17
  18 // { dg-do run { target c++14 } }
  19
  20 #include <experimental/algorithm>
  21 #include <random>
  22 #include <testsuite_hooks.h>
  23 #include <testsuite_iterators.h>
  24
  25 using __gnu_test::test_container;
  26 using __gnu_test::input_iterator_wrapper;
  27 using __gnu_test::output_iterator_wrapper;
  28 using __gnu_test::forward_iterator_wrapper;
  29
  30 std::mt19937 rng;
  31
  32 void
  33 test01()
  34 {
  35   const int pop[] = { 1, 2 };
  36   int samp[10] = { };
  37
  38   // population smaller than desired sample size
  39   auto it = std::experimental::sample(pop, pop + 2, samp, 10, rng);
  40   VERIFY( it == samp + 2 );
  41   VERIFY( std::accumulate(samp, samp + 10, 0) == 3 );
  42 }
  43
  44 void
  45 test02()
  46 {
  47   const int pop[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 };
  48   int samp[10] = { };
  49
  50   auto it = std::experimental::sample(pop, std::end(pop), samp, 10, rng);
  51   VERIFY( it == samp + 10 );
  52
  53   std::sort(samp, it);
  54   auto it2 = std::unique(samp, it);
  55   VERIFY( it2 == it );
  56 }
  57
  58 void
  59 test03()
  60 {
  61   const int pop[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, };
  62   int samp[5] = { };
  63
  64   // input iterator for population
  65   test_container<const int, input_iterator_wrapper> pop_in{pop};
  66   auto it = std::experimental::sample(pop_in.begin(), pop_in.end(),
  67                                       samp,
  68                                       5, rng);
  69   VERIFY( it == samp + 5 );
  70
  71   std::sort(samp, it);
  72   auto it2 = std::unique(samp, it);
  73   VERIFY( it2 == it );
  74 }
  75
  76 void
  77 test04()
  78 {
  79   const int pop[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
  80   int samp[5] = { };
  81
  82   // forward iterator for population and output iterator for result
  83   test_container<const int, forward_iterator_wrapper> pop_fwd{pop};
  84   test_container<int, output_iterator_wrapper> samp_out{samp};
  85   auto it = std::experimental::sample(pop_fwd.begin(), pop_fwd.end(),
  86                                       samp_out.begin(), 5, rng);
  87
  88   VERIFY( std::distance(samp, it.ptr) == 5 );
  89
  90   std::sort(samp, it.ptr);
  91   auto it2 = std::unique(samp, it.ptr);
  92   VERIFY( it2 == it.ptr );
  93 }
  94
  95 int
  96 main()
  97 {
  98   test01();
  99   test02();
 100   test03();
 101   test04();
 102 }